
(begin
  (define a (Pt -1 0))
  (define b (Pt 0 0))
  (define c (Pt 0 1))
  (define d (Pt -1 1/2)))

(pt-distance a b)			; => 1

(pt->list (pt-+ a c))			; => (-1 1)

(pt->list (pt-inverse d b))		; => (1 -1/2)

(map pt->list
     (pt-generate-line (make-pt 0 0)
		       (make-pt 5 0) 
		       1)) ; => ((0 0) (1 0) (2 0) (3 0) (4 0) (5 0))

(map pt->list
     (pt-generate-line (make-pt 5 7/5)
		       (make-pt 10 2/5) 
		       1)) ; => ((5 7/5) (6 6/5) (7 1) (8 4/5) (9 3/5) (10 2/5))
